[UX][Reviews] Approve an MR from any tab
Release notes
The "Approve" button appears in all tabs of a merge request.
Problem to solve
As a reviewer, I will typically look at the list of commits, the changes, and possibly the pipelines. However, to finally approve the merge request, I have to navigate back to the "Overview" tab to click the Approve button.
Intended users
Anyone doing reviews:
User experience goal
Save one click and a bit of mouse mileage during a very common workflow.
Proposal
When the logged in user is authorized to approve an MR (i.e. when the Approve button appears in the Overview tab), add an Approve button to the right sidebar (issuable-sidebar).
This duplicates the Approve button in two places (on the Overview and on the issuable-sidebar), so maybe it's better to move the entire Approval section to the sidebar.
Another alternative is to add the Approve button to the review-bar that appears when a comment has been added. However, that only appears if a comment has indeed been added (and you want to be able to approve without adding comments as well). Also, IIUC approval and review comments are currently completely unrelated in the business logic, so tying them to the same review-bar is probably not appropriate.
Permissions and Security
No impact - this only adds UI, no change to the business logic.